a Guide to Management - USGS National Wetlands Research Center

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Figure 16. Two-year-old loblolly pine plantation in Gulf Hammock. Dead live oaks from the former stand of hydric hammock were girdled rather than cut, because of their size and current lack of economic value. for turkey decline much earlier in the life of the pine stand (Felix et a7. 1986). During the latter half of the first decade, thicket-loving species 1 i ke go1 den mouse (Ochrotomys nut - ta77i), brown thrasher (Toxostoma ru- fum) , hooded warbler (Wi7sonia cit- rina), whi te-eyed vireo, and rufous- sided towhee (Pipi70 erythrophtha7mus) may do quite well. Following the first decade, however, there is a long period of several decades in which the pioneer species are gone and the mature hammock species have not yet re- turned in abundance. During this period, the range value is very low, and even the very adaptable species like deer, raccoon, and wild turkey make less use of the forest. Furthermore, this intermedi ate-aged, second-growth forest is more monotonous and less open visually than either a very young (first decade) or a mature forest. Unless a cleared path is provided, hy- dri c hammocks become impenetrable to most recreationists two or three years following a clearcut and do not open up enough for much use for several decades. Impacts on soils, hydrology, and water and site qua1 ity can be caused by the heavy equipment used in logging and site preparation. Skidders can leave ruts 0.6 m wide and 1 m deep if the ground is soft. If the same route
is repeatedly followed, a 3 m wide canal may be created that becomes a permanent feature of the property. Soils may be compacted and ponded by repeated passes of heavy equipment on log decks and skid trails (Table 6). These logging disturbances may occupy a large proportion of the harvested area--34% on average in logged lahTolly oire forests (H~tche!! et 21. 1970). he disturbed soils are slow to recover and productivity is re- duced, part i cul arly where compaction is combined with high soil moisture. If deep tracks go up and down slope, following the water flow direction, considerable erosion may occur, in which increased sediment loads are carried to streams, swamps, ponds, or lakes, Ruts can channelize the flow where previous drainage was sheet flow over the surface, accelerating runoff and reducing the water retention and filtering capacity of the wetland. The influences of forestry practices on the water qua1 ity of blackwater rivers and estuaries are of particular cancern in the southeastern United States (Netter and Gregory 1985). Be- cause bl ackwater rivers usual ly con- tain low levels of nutrients (Wharton et a7. 1982), even small increases in nutrient loading may significantly al- ter these systems. Elevated flows of freshwater to estuaries, especially in late spring and early summer, may re- duce salinity to levels below those to1 erated by invertebrate and fish specizs that use the estuaries as breedi ng and nursery areas. Fortu- nately, drw to the flat terrair! of hydric hammocks and the generally low erodibil ity of forested wetland soils in Florida (Riekerk 1983), erosion and sediment loss are probably not major consequences of timber harvesting in these wetlands. Increased sediment, nutrient, and water exports are probably temporary, lasting one year or less after the work is completed. In the southeastern ccastal plain, nutri ent and sediment losses associated with erosion, leaching, and runoff from cleared wet1 and forests are small and short-term (Table 7). Of the steps involved in converting a hard- wood wetland forest into a loblolly pine plantation, drainage has by far the most deleterious effect on water quality (Askew and Williams 1984; 1986). In slash pine dominated wetlands, most nutrient concentrations in runoff return to control levels during the second year after harvest and site Table 6. Effects of logging on physical properties of coastal plain soils supporting loblolly pine stands (from Hatchell et al. 1970). Infiltration rate is a measure of soil drainage. Air space Is negatively correlated with soil-water content. Infiltration Bul k degsi ty rate of water Air space Location of soil sample (cm/hr) (% by volume) Log deck Skid trail Undisturbed forest
Page 2 and 3: t ,blzrnry Na'jonal Wetlands Resear
Page 4 and 5: f$c 3piniccs and rec~mendations exp
Page 6 and 7: CONVERSION TABLE Metric to U.S. Cus
Page 8 and 9: 5.4 WATER MANAGEMENT . . . . . . .
Page 10 and 11: 28 Effects of forest thinning on th
Page 12 and 13: ACKNOWLEDGMENTS We are grateful to
Page 14 and 15: SAN FELASCO ORANGE LAKE SILVER SPRI
Page 16 and 17: sweetgum timber, with values reachi
Page 18 and 19: temperate-zone di stpi butions that
Page 20 and 21: Table 2. (Continued). Scientific na
Page 22 and 23: from numerous field trips and consu
Page 24 and 25: Species Table 3. Endangered or thre
Page 26 and 27: coast is particularly important for
Page 28 and 29: along creeks in flatwoods and sand-
Page 30 and 31: 3.4 PRE-COLUMBIAN HUNiiNG AND GATHE
Page 32 and 33: Figure 4. Hog pen in coastal hydric
Page 34 and 35: were heavily looted, and most of th
Page 36 and 37: 4.1 OWNERSHIP CHAPTER 4. PRESENT US
Page 38 and 39: Figure 8. Limerock pit in inland hy
Page 40 and 41: still proceeds in these areas and c
Page 42 and 43: Figure 11. An extensive clearcut of
Page 44 and 45: Figure 14. Bedding rows for pine se
Page 48 and 49: Table 7. Nutrient and sediment expo
Page 50 and 51: such as pine flatwoods, prairie, or
Page 52 and 53: . loo/: 90 0. virginiano Q. @ incon
Page 54 and 55: volume and will hold all the runoff
Page 56 and 57: experiment, seed7 ing density was s
Page 58 and 59: canoeing (on adjacent rivers and in
Page 60 and 61: 9 1940 1980 2020 2060 YEAR Figure 2
Page 62 and 63: In prehistoric times, periodic fire
Page 64 and 65: Figure 24. lnvasion of hydric hamnx
Page 66 and 67: 14. Is recreational use important a
Page 68 and 69: the canopy, health, and straightnes
Page 70 and 71: a1 though there is considerable var
Page 72 and 73: oots to which it is root-grafted, b
Page 74 and 75: cattle. Prescribed burns often are
Page 76 and 77: eftluent wniie returnir~y Ii~e whta
Page 78 and 79: - the mesic hammock upslope also ha
Page 80 and 81: arred owl, flycatchers, tufted titm
Page 82 and 83: Figure 29. Debris pile on a hydric
Page 84 and 85: . -.... 1 IYGL), wi~iit~ iire an ef
Page 86 and 87: FE r~t, si-iliai i ar.eas itray not
Page 88 and 89: in order to protect watershed, wi l
Page 90 and 91: management efforts that can benefit
Page 92 and 93: Bryant, W.C., editor. 1872. Davjs,
Page 94 and 95: Harlow, R.F. 1959. An evaluation of
Page 96 and 97:
I S F n A understanding . American
Page 98 and 99:
Soil Sci. Soc. Amer. Proc. 47:591-
Page 100 and 101:
Tuschall , J.R., P.L. Brezoni k, an
Page 102:
Hvdrick Hammocks: a Guide to Manage
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